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Engineering vehicles & heavy plant
Engineering vehicles & heavy plantTunnel Boring Machine (TBM)

TBM Dorothy - HS2 Long Itchington Wood Tunnel

Long Itchington Wood, Warwickshire, UK · 2021-2023 · £87.7bn - £102.7bn (HS2 project total, 2025 prices)

The judgement call

Account-gated at launch

Named after Dorothy Hodgkin. Completed its 1.6km first bore and then a second bore. It was the first TBM on the Midlands section of HS2. Lessons learned from Dorothy's excavation helped with other TBMs like Mary Ann.

Key engineering challenges

Tunnelling through varying ground conditions. - First deep tunnel on the HS2 project.

Project facts

Client / owner
HS2 Ltd.
Lead contractor
Balfour Beatty VINCI (BBV)
Lead designers
Project type
new build
Scale
TBM length: 125m; Tunnel length: 1.6km (1 mile) twin-bore tunnel
Disciplines
civil; structural; mechanical; electrical; systems; tunnelling; geotechnical
Standards & frameworks
UK railway standards, CDM Regulations (implied).

Sources: New Civil Engineer (https://www.newcivilengineer.com/latest/hs2-tbm-dorothy-completes-second-drive-underneath-long-itchington-wood-30-03-2023/) - Balfour Beatty VINCI (https://balfourbeattyvinci.co.uk/hs2-marks-major-construction-milestone-at-long-itchington-wood-tunnel/) - TUC Magazine (https://tucmagazine.org/hs2-tunneling-team-celebrates-breakthrough-at-long-itchington-wood-tunnel/) - BBC News (https://www.bbc.com/news/articles/cpq2len1weyo) - HS2.org.uk (https://www.hs2.org.uk/building-hs2/tunnels/twin-bore-tunnels/)